Adjustment circuit for registration control device



April 24, 1962 .1. c. FROMMER ADJUSTMENT CIRCUIT F'OR REGISTRATIONCONTROL DEVICE Filed Nov. 4, 1958 3 Sheets-Sheet 1 NNN QNN.

ADJUSTMENT CIRCUIT FOR REGISTRATION CONTROL DEVICE Filed Nov. 4, 1958 J.C. FROMMER April 24, 1962 3 Sheets-Sheet 2 EAW WIR/.UA h;

April 24, 1962 J. c. FROMMER 3,031,118

ADJUSTMENT CIRCUIT FOR REGISTRATION CONTROL DEVICE Filed Nov. 4, 1958 3Sheets-Sheet 3 K Ml N2 H, M2

A. A f v 3,031,118 ADJUSTMENT CIRCUIT FOR REGISTRATION CONTROL DEVICEJoseph C. Frommer, Cincinnati, Ohio, assignorfto Hurletron Incorporated,Danville, Ill., a corporation of Delaware Filed Nov. 4, 1958, Ser. No.'771,821 27 Claims. (Cl. 226-23) This invention relates generally to thecontrol of registration of two or more operations being performedrepeatedly and continuously upon a moving'web, and more particularlyrelates to achieving a fine adjustment of the control through anelectrical circuit whereby to obviate the need for adjusting certainsignal producing means manually.

Such adjustment as contemplated by the use of the invention herein isexceedingly ne and enables a very high degree of accurate registrationto be achieved by controlling the occurrence of certain electricalsignals whose relationship determines the degree of registration. Theinvention is believed important because, in addition, the adjustmentscan be made wthout the need for stopping the movement of the web andwithout making physical changes in the position of any signal producingmeans whatsoever.

To appreciate and recognize the status and the nature of the inventionherein, reference may be had to U.S. Patent 2,518,325 issued August 8,1950 to S. C. Hurley, ir. and to U.S. Patent 2,840,371 issued June 24,1958 to the applicant herein, both of said patents being assigned tolthe same assignee as the application herein.

The subject matter of said patents comprises devices whose purpose it isto synchronize the performance of two consecutively executed operationsupon a moving web in such a manner .that notwithstanding the operationsa-re performed at stations spaced along the length of the web, theyoccur in perfect registration with one another. The principal examplesgiven in both of said patents concern high speed, multi-color printingpresses in which it is desired that there be substantially perfectregistration of consecutive impressions produced by consecutiveprintting cylinders or the like. IIn said patents there are describedvarious circuits which function in accordance with a similar principle.

According to this principle, the first printing station which the webreaches during its travel applies a certain indicia upon the moving webalong with the printed text or other matter. The indicia may be in theform of a small mark or series of marks recurrent along the length ofthe web. The web travels to the second printing station andthe secondimpression, in another color, is applied to the web by the type orengravure or other means carried by the second printing cylinder, forexample. In any event, the two impressions or printings are required tobe in as perfect registration as possible, the end result of suchregistration being a realization of the effect desired from the originalcomposition, both color-wise and impression-wise. The more accurate andprecise the registration, the better the effect and the higher thequality of the printed result.

At the second station, secured to the shaft of the second printingcylinder or other rotational means which is applying the secondimpression, or at least rotatively coupled therewith, there is provideda magnetic member States Patent *if ICC often called a flipper in theart, which rotates past one or more electromagnetic polesV whereby togenerate current in the windings enwrapped about the said poles. Theproduction of such current provides a signal with each passage of theipper past one pole related substantially instantaneously with therotation of the rotational means -at the second printing station, suchas for example, the second impression cylinder.

At another position along the web, which conveniently may be closeA tothe second impressioncylinder, there is positioned what is known in theart as a photoelectric scanner, including a source of illuminationdirec-ted upon the web to illuminate the path of movement of the marks,and a photoresponsive device arranged to receive the reflection of theillumination from the web. Each time that the mark appears, the amountof reflection from the web is decreased during the time that the mark ispassing, and the photo-responsive device, which may be a photoelectrictube or cell, will be affected. The effect may be a change in thecurrent output of the tube. The reilection from the web will obviouslybe greater when there are no marks, and the amount of current producedthrough photosensitivity will substantially decrease with decrease inreflected illumination as the mark is passing.

In this manner, the output of the photo-responsive means is used toproduce a scanner signal, which in effect is directly related to theimpression upon the web applied `at the rst printing station, by the rstimpression cylinder.

The outputs of the two signal producing means, namely the structurecomprising the fiipper and poles, often called a magnetic timer, and thescanner are compared in a. suitable device to provide an error signal.The comparison device is usually in the form `of an electronic circuitwhich has the ability to complete the direction and amount ofvdifference in the time occurrence of the two signals and provide apolarized output or an output in one of two different channels which isadapted to be applied to means physically operating upon the machine tobring the two printed impressions into registration.

In printing presses the correcting means usually comprise an idlerroller between Ithe two printing stations which is mounted in such amanner that its entire axis may be 4moved to change the distance thatthe web must travel in passing from the tirs-t impression cylinder tothe second. Such a construction is shown in simplified diagrammaticmanner in U.S. Patent 2,840,372 issued Iune 24, 1958 to R. J. Alhand andassigned to the assignee of this application. The mounting for the idlerroller may be movable by means of a reversible electric motor which isconnected to the output of the registration control circuit. Theregistration control circuit may operate into two relays, one of lwhichwill serve to apply power tothe electric motor for translating the axisof the correction roller in one direction, and the other of which willserve to apply power to the electric motor for translating ythe axis ofthe correction roller in the opposite direction. Usually thesedirections are up and down. In moving the axis of the correction rollerupward, the web length between printing stations is increased, and inmove ing the axis downward, the webv length between printing stations isdecreased. The registration control circuit will provide an errorvoltage which will energize one or the other of the `output relays, orneither, depending upon the signals which are applied to the circuit.

Conveniently, when the printed impressions are in perfect registration,the signals are in perfect synchronism, and there is no error signalproduced in the computer, so that the correcting means is not activated.The condition of perfect synchronism of the signals can be achieved, andhas been achieved in many apparatuses in commercial use, through thephysical adjustment of the positions of the scanner and magnetic timer,the one linearly relative to the length of the web, and/ or the othercircumferentially relative the shaft of the second impression cylinder.Such adjustment is made until the signals are in perfect synchronism forthe condition of perfect registration of the two consecutiveimpressions. The physical adjustment of the two signal producing meansis a matter of changing fastening means, and this can be done usuallywith only a limited degree of accuracy. In most known installations,theposition of the poles of the magnetic timer is changed, all of saidpoles for a given timer being mounted on a shoe which can be manuallyrotated arcuately relative to the axis of the cylinder which mounts theflipper. While this can be done while the press is operating, theachievement of perfect registration is a matter of trial and errorinvolving repeated changes in the position of the shoe. Obviously, thescanner cannot be moved in its position while the press is in operationwithout danger to the operator.

Probably the primary object of the invention, which should be mentionedat this point, is to provide means whereby the initial disposition ofthe signal producing means may be coarsely set and tine adjustments madein the occurrence of the signal from said signal producing meanselectrically by means of a simple manual control. Such manual controlmay move a wiper or slider of a potentiometer, thus eliminating the needfor ne adjustment of the physical position of one or the other of thesignal producing means. Since the manually movable member, ascontemplated by the invention, merely changes component values of anelectrical circuit, it may be positioned immediately adjacent anyposition of the press where the results of printing impressions may becarefully observed for registration so that the observer himself maymake the necessary line adjustment. Thus, there is no need forestablishing communication between the observer and an operator makingthe physical adjustments, as heretofore might have been required, andthe amount of trial and error is kept to a bare minimum.

It should be understood that the need for making adjustments in therelative occurrence of the two signals obtains only when synchronism ofthe signals does not produce perfect registration. If the perfectregistration condition thus described exists, there is no need to changethe positions of the signal producing means, either physically orelectrically through the use of the invention herein. The adjustmentdescribed will therefore usually take place only during the setting upof a project to be run on the press. The invention enables this to bedone easier and faster. Once the desired conditions have been achievedfor perfect registration, the position of the manual control of theinvention is not changed, unless something unusual should occur during arun.

The invention will better be understood with a short explanation of what,occurs to the printed impressions if the signal producing means are notperfectly positioned relative to the length of the web. If, for acondition of perfect registration, the signal from the magnetic timeroccurs too soon, that is, before the occurrence of the signal from thescanner, the computer will produce an error signal and the correctingdevice will be driven to change the length of web subtended betweenprinting stations until the signals occur in synchronism. The rstimpression would then be adjusted by the correcting means to occursooner to force the electrical signals to be synchronized, irrespectiveof register conditions; and the final result would be that when thesignals coincide, the second impression would be leading the first. Thecomputer cannot be affected by the objective evidence of registrationsince it is acted upon by the signal producing means irrespective oftheir relations to the impressions made at the printing stations, and ifthe signals are not coincident, the computer will strive to produce anerror signal to make them so-irrespective of what happens to theregistration of impressions.

The typical installation of apparatus of the type described in thepatents referred to above includes means for shaping the signals todesired configurations prior to comparing the same, and various circuitsare provided to achieve the desired wave shapes. In said Patents2,518,325 and 2,840,371, the signal-s which are compared are rst changedinto substantially square waves by means of a so-called flip-flopcircuit, and these square waves are conveniently related in time to thepassage of the flipper between two poles of the magnetic timer. Theinvention herein preferably comprises a circuit which is electricallyinterposed between one of the signal producing means and the comparisondevice or computer, to change the position of the critical part of thesignals along their time axis so that the result `is a simulation ofwhat would occur if the entire signal producing device were physicallymoved one way or the other. Thus, if the signal produced by the magnetictimer were delayed by the apparatus of the invention and the scannersignal were not, the eliect would be the same if the magnetic timer hadbeen physically changed, as for example, by moving the pole mountingshoe to give its signal later in time.

As stated above, the signal delay is obtained in this invention throughthe change of components 0f an electrical circuit. Delay of pulses inelectrical circuits can be achieved in several ways, but the amount ofdelay which occurs in known circuits is related to the constants of thecircuit, irrespective of the recurrence rate of the pulses, assumingthat the amount of delay is always substantially less than the timebetween pulses. In other words, if a pulse is to be delayed by a givennumber of micro-seconds, through the use of a network of some knowntype, all pulses will be delayed by that time, irrespective of the rateat which the pulses occur. This, of course, is not practical formachines, the speed of which is not invariably constant, either bydesign or by chance, because in such machines the rate at which thepulses occur varies with the speed of the machine. For any given set ofconditions, the amount of delay, measured in length of web representedby the delay, is constant. Therefore, the amount of delay measured intime varies, being `a direct function of the speed of the machine, orpress, in the case of the specific system discussed herein.

The invention herein utilizes an unobvious manner of prividing for delayof an electrical signal such as pruduced in a device as described in theabove patents, in which the delay of a given signal is inverselyproportional to the speed of the press. ln other words, the faster thepress, the less the delay time, and vice versa.

The provision of means to cause this phenomenon forms an importantobject of the invention. The electrical circuit of the invention willprovide a delay of a signal whose time duration is inverselyproportional to the speed of the press. Thus, if at a web speed of 1500feet per minute, a given condition of the apparatus provides for a delayof signal which corresponds to tivethousandths of an inch along the web,at 750 feet per minute the delay of signal must also provide the samelinear delay. The press is going at a much slower rate of speed,however, and the actual time represented by the linear delay at theslower rate is twice the time represented by the linear delay at thefaster speed. The delay in time, therefore, must be doubled when thespeed of the press is halved. In addition, this same relationship, thatis, the inverse proportion must be preserved for all speeds of thepress. The invention herein accom` plishes this.

Objects of the invention include the provision of novel electroniccircuitry of relative simplicity for accomplishing that which has beendescribed above; the provision of 'means for producing a pulse or shapedsignal from one of the signals produced by the signal producing meanswhich will have an effective leading and trailing portion `forming aconstant angle so that the variation of the duration of the leadingportion will result in proportional variation of the duration of thetrailing portion; the provision of means to maintain the leading andtrailing portions of said pulse substantially linear in order topreserve the constant angle, notwithstanding that the shape of at leastone of said portions is caused by the iiow of current in a condenser;the provision of an electronic circuit requiring no relays or the like,whereby the same may be readily installed by simple modification in manyregistration control apparatuses in use today.

The invention gives rise to many corollary advantages which stern fromthe ability of the press operator to cause the signals from the scannerand magnetic timer to conicide at registration of consecutiveimpressions, notwithstanding the fact that the physical positions of thescanner and magnetic timer are not perfectly adjusted. In setting up thepress, a great deal of time need not be expended in locating the iiipperwith respect to the engravure or impression of the cylinder to the shaftof which the flipper is secured; likewise the location of the flipperrelative the poles of the magnetic timer need not be sought withprecision. Pressmen are skilled sufficiently to make the adjustmentsWithin a fair degree of the range of an electrical circuit easilyconstructed in accordance with the invention. Because of this, themounting of the flipper and the yoke or shoe of the magnetic timer maybe considerably simplified.

Many other objects of the invention will lbecome apparent to those whoare skilled in this art, and while the apparatus will be described inconnection with a printing press, it should be obvious that it isequally applicable to other systems in which there is a moving web uponwhich consecutive operations are to be performed. The structure itselfis also capable of considerable variation from the specific examplesshown in the drawings and described hereinafter.

In the following description, preferred embodiments are set forth inconsiderable detail as required by the patent laws, and the variouscircuits and diagrams illustrated in the drawings are explained in orderto enable a complete and clear understanding of the invention to be had.In addition to exposition of the details of structure, the theory uponwhich the invention and operation thereof is based will be set forth,but only for the purpose of clarity and not by way of limitation, sincethe structure which is described and claimed hereinafter produces thefunctions which are necessary for the achievement of the objectsdescribed, and it is immaterial whether the theory or theoriespostulated are valid.

In the drawings:

FIG. l is a block diagram of a registration control system installed ina multiple impression printing press, showing the relationship of theinvention and the other parts of the system.

FIG. 2 is a circuit diagram of apparatus embodying the invention andenabling the delay of a signal to simulate the effect of physicallyadjusting the position of the signal producing means.

FIG. 3 is a chart showing the time relationships between the varioussignals occurring in the circuit of FIG. 2, wave shapes designated A',A, B and C representing the wave shapes for a press speed half of thepress speed for which the wave shapes designated D, E and F representsignals.

FIG. 4 is an enlarged view of the voltage wave shape of a signalappearing at a terminal of the condenser C-4 of FIG. 2, the wave shapebeing shown for two speeds of the press, one being twice the other.

FIG. 5 is a view similar to that of FIG. 4, but in this 5 view the pressspeed is constant, -but two configurations of the signal are shown toillustrate the effect of relaying the signal through the use of theinvention to simulate physically moving a signal producing device.

FIG. 6 is a diagrammatic View of a magnetic timer.

The invention, as alluded to above, is applied to a registration controlsystem which is complete and will provide registration adjustment toovercome leading or lagging by one impression, providing the signalproducing means are perfectly positioned relative to the respectiveimpressions of the two printing stations or cylinders. In such a system,the output signals 'from the magnetic timer are usually amplified andshaped in some sort of pulse Shaper to serve as gating means withrespect to the signals which are received from the scanner. The scannersignals themselves may be pre-amplified and also shaped to certainrequired configurations.

Specifically, in the structures described in the patents referred toabove, the output from the magnetic timer is applied to an electroniccircuit whose output is substantially a square wave. The square Wave isused to gate the circuit to provide the desired error voltage output.The trailing end of the square wave is that end with which control isachieved, since that end is the termination of the gate, and is used tooperate upon the signal which is received from the scanner and itsassociated circuits.

The problem of providing a circuit in which by the simple adjustment ofa manual control member, such as a small knob, the duration of thesquare Wave can be varied is complicated by the requirement that in anyevent the duration of the square wave must be inversely proportional tothe speed of the press. To meet this requirement, the amount of delaywhich is applied to the circuit must also be inversely proportional tothe speed of the press irrespective of variation thereof.

In FIG. l there is illustrated diagrammatically a system of the typediscussed herein showing how the invention is applied thereto. Thereference character 10 designates a web, such as a web of paper passingthrough a high speed, multi-color printing press, the direction ofmovement being indicated by the arrows 12. The web is shown passing arst printing station at which there is located a `first impressioncylinder or roll i4 which applies a first impression of one color uponthe web and also applies a small marginal mark 16 along the webrecurrently, whose purpose it is to establish the position of the iirstimpression on the web 10. The impression is not shown in the diagramsince its presence is not needed to explain the invention.

Further along the web 10 there is a second printing station where asecond impression cylinder or roll 18 applies a second imprintedimpression (not shown) directly upon the rst impression, and in a secondcolor. Obviously the two impressions may comprise or be a part of acomplete composite printing that eventually will be a magazine,newspaper, rotogravure section of a newspaper or the like, and insevera-l colors. The two impressions must be in substantially perfectregistration in order to produce the effect intended by the composer.

The shaft Zt) of the second impression cylinder 18 is connected to themagnetic timer 22` which has previously been mentioned. The details ofthis device are wellknown and hence are not elaborated upon here. Such amagnetic timer is shown diagrammaticaily in FIG. 6. The signal outputfrom this device comprises the input to a pre-amplifier and pulse Shaper24. The pre-ampli'er and pulse shaper 24 may take several differentforms, but for the purpose of this invention, the output of this circuit`at the point 26 preferably is a square wave. The square wave occurs insynchronism with the passage of the flipper past two poles of themagnetic timer 22. and in synchronism with the rotation of the cylinder18 since the ipper (see 56 in FIG. 6i) is mounted on the shaft 20. Forconvenience the block 24 will be referred to merely as a pulse shaper,since the pre-amplifier is not essential. Conceivably the structure ofthe timer 22 may be modified such that the output may directly be asquare Wave signal or any suitable signal having two parts separated bya time depending on press speed. With this in mind, reference made inthe claims to signal producing means will define either the magnetictimer 22 alone, in combination with a pre-amplifier and/or fiip-iiopcircuit, or any device the output of which is a square wave or othertwopart signal whose duration and occurrence are related to the rotationof the cylinder .18 and hence also related to the impression applied tothe web by said impression cylinder 18. In the discussion which follows,the signal related to the second impression cylinder is usually calledthe first signal (because the means producing the same are locatedforward of the web relative to the scanner).

The descriptive term square wave is a relative one, since it is rarethat the square wave referred to is geometrically rectangular, as shownin FIG. 3. This is an idealized configuration, the actual shape varyingsubstantially from the perfect form, but still providing the requiredfunctions by virtue of its form.

The signal which appears at 26 and which comprises a square `wave isordinarily applied to the comparison circuit or computer 2S where it iscompared with another signal applied at the input 30. This latter signalis obtained directly from the web 10 itself. T-he marks 16 areilluminated by means of a source of light 32 and are reflected to aphoto-responsive device 34 which includes a photoelectric cell or thelike. The source of light 32, photo'responsive means 34, and otherapparatus comprise the scanner 35, being practically always mounted in asingle housing, including the optical system for focussing the light,etc. The passage of the marks 16 causes changes in the current flowingin the photo-sensitive device 34 which gives rise to signals which maybe preamplified and shaped in the circuit 36 before being applied to thecomparison circuit 28.

The output of the comparison circuit appears at 38 and is applied tomeans such as relay circuits which are symbolized generally by the block40, producing an error voltage of one or another type to drive the motor42. This motor is connected by suitable means such as a rack 44 andpinion 46 to a yoke or frame 48 which mounts an idler roller 50. Theraising or lowering of the yoke or frame 48 through rotation of themotor 42 one direction or the other either increases or decreases thedistance subtended along the web between the impression cylinders 14 and18 and hence changes the conditions producing the error voltage. Anyother means including differential gearing could be used to change thisdistance so long as it serves to adjust the positions of the impressionsmade by the respective cylinders relative one another.

The system of FIG. l as thus far described is wellknown. The output ofthe pulse Shaper 24 appearing at 26 is applied directly to thecomparison circuit Z8 in known structures, and when the signals from thescanner 35 and the magnetic timer 22 are in perfect synchronism, therewill be no output signal appearing at 38, and the motor 42 will not beenergized. Under these circumstances, ideally the two impressionsapplied at the printing stations by the cylinders 14 and 18 are inperfect registration. During setup, if this were found not to be thecircumstance, either the physical relationship of the magnetic timer 22with respect to the shaft 20, or the position of the scanner 35 withrespect to the web 10, would be changed to cause perfect registration tooccur.

The difficulties of accomplishing this for accuracies of the order ofseveral thousandths of an inch have been described, and hence thecircuit designated 52, the delay circuit, has been interposed betweenthe pulse shaper 24 and the comparison circuit 2S. A part of the delaycircuit 52 includes a manual control 54 by means of which the linearamount of delay introduced can be varied.

For any given setting of 54, the linear delay will be constant,irrespective of the speed of the web 10. This delay circuit changes thetime of arrival of the pulse from the magnetic timer thereby simulatinga physical change in the position of the timer v'22, but without theneed for actually making such physical change. The change, as referredto, comprises a delay, which means that the initial adjustment of thetimer and scanner should be made with the delay circuit 52 providing adelay equal to about half of its range, so that there is sufficientlatitude for adjustment on both sides of the initial condition. This ismerely a matter of technique in use, and each user may vary the same.

Attention is now invited to the circuit of FIG. 2 which is an embodimentof the invention comprising what has been termed the delay circuithaving the manual control 54 of FIG. l. The same circuit with slightmodifications, as will be described, comprises a basic form of theinvention without certain refinements which make for a better structure.ln this circuit, the vacuum tubes or valves are designated by thereference characters V-l t0 V-S, the resistors are designated by thecharacters R-l to R-SZ, the capacitors are designated by the referencecharacters C-l to C-S, and the potentials applied to the various partsof the circuit are marked by the value of the voltage for a typicalstructure. The voltage sources are not shown, since these may be anyconventional means such as batteries, power supplies and the like andwill probably be obtained from other parts of the system which requiresuch potentials for their own purposes.

The magnetic timer 22, in conjunction with the pulse shaper 24 providesthe square wave signal which is shown at A and again at D in FIG. 3. Thesignal is negative going and its leading edge occurring at the time M1is commenced when the flipper S6 which is secured to the shaft 20 (seeFIG. 6) passes the pole or magnetic circuit MCl. The signal remains at aconstant negative value during what is termed the lead inspection zoneas the flipper 56 is passing to the next pole or magnetic circuit MC2 atwhich time the signal becomes zero once more. This time is representedin FIG. 3 at A by the character M2 which identifies the time as thatwhen the pole MC2 is passed. As for the wave form in FIG. 3 at D, thesame zone is represented by the distance from M'1 to Mz, the speed ofthe press being doubled and hence the length of the signal along thetime axis being halved.

This signal A is applied at S9 through the coupling condenser C-1 andthe resistor R-13 to the grid 61 of the left hand section of the twintriode V-l. The cathode 62 of this section of the tube (designatedhereinafter V-l-L) is connected to a source of potential having arelatively substantial negative value, shown as volts in FIG. 2. Theplate 64 is connected to the junction J-l, which connects one terminaleach of the resistors R-7, R-9 and R-10 for a purpose to be described.The grid 61 is connected to the cathode 62 by a grid leak resistor R-land hence, when there is no signal applied to the grid 61, said grid 61and cathode 62 will be essentially at the same potential, and V-l-L willbe conducting saturation current, whereby the plate 64 will bemaintained at a voltage below zero, say -1'00 volts D.C., below ground.

When the negative going potential of the signal A of FIG. 3 is appliedto the grid 61 driving the grid 61 negative, the left hand section V-l-Lwill be cut off, and the voltage on the plate 64 will consequently riseto a high potential which is a characteristic of the tube section V-l-Lfor an absence of plate current.

In the meantime, the right hand section of the tube V-1 (designatedhereinafter V-LR), has also been conducting saturation current, beingconnected to receive the input from the pulse shaper 24 whichcorresponds to an amplified signal which occurs when the flipper 56passes the second pole MC2. This signal is applied to the terminal 69through the coupling condenser C-2 to the grid 70 of V-l-R, the `plate71 being connected to high voltage B-lsupply 65 through the droppingresistor R-Z and the cathode 72 being connected to ground 63. Note thatthe grid 70 -is connected through a resistor R-3 to a high positivepotential source 73- which may be of the order of 150 volts D.C., andhence it normally draws grid current. Because of this the tube sectionV1R is conducting saturation current, which places the plate 71 at arelatively low potential.

The pentode V-Z has its grid y74 connected to the plate 71 of V-l-Rthrough a coupling condenser C-3 and to the center tap of the voltagedivider lR-S, -R-G- connected between two points of negative potential,shown at 66 and 76 as -l50 volts D.C. and -30O volts D.C. respectively.Thus, with the grid 74 of the pentode V-Z very negative with respect tothe cathode 77, the pentode V-Z will be cut off so long as there is sosignal on the grid 74. The plate 78 of the tube V-2 is connected to theplate 64 of V-l-L through the resistor R-7, but the plate 78 is alsoconnected to the upper electrode of the storage condenser C-4 at thejunction J-2, to the cathode 3l) of the left hand section of the dualdiode tube V-4 (hereinafter called V-4-L), and to the grid 81 of theleft hand section of the twin triode V-3 (said left hand Vsectionhereinafter called V-3-L).

The pentode V-Z has its screen grid S2 connected through the resistor R8to ground which actually is at 150 volts D.C. above its cathode 77which, it will be noted from FIG. 2, is connected to the point ofnegative potential 66, shown to be at -150 volts D.C. The voltage of thescreen grid 82, however, is limited by the plate 83 of the right handsection V-4-R, the cathode 84 of this latter tube section beingconnected to the center tap of the voltage divider R-29, R-30 whichextends between ground 63 and a substantial negative D.C. potential,such as the point 66 which is maintained at about -l50 volts D C.

The signal from the pole MC2 which has been amplilied appears somewhatas shown at A in FIG. 3 and, as will be seen from an examination of thecircuit, its positive going portion will have no effect upon the tubeV-Z since the plate 71 of V-l-R will continue to be low in potential,the right hand section V-l-R being in saturation. As for lthe negativegoing portion however, this will serve to cut oif the right hand sectionV-l-R, raise the potential of the plate 71, and will cause the tube V-Zto conduct a current defined essentially by the resistor R-S for theduration of the negative going portion of the signal A.

Considering now the signal A which was applied to the tube section V1Las shown in FG. 3, when this signal goes negative and the tube sectionis cut off, the condenser C-4 will commence to charge positively throughthe high ohmage resistor R-`7 (which may be of the order of 3 megohms).The current path is from the junction I1 through the resistor R-7 to thejunction I-Z which is common with the upper electrode of the condenserC-4. This charge occurs at a relatively slow rate, but is linear, aswill be brought out shortly, notwithstanding that the normal condensercharge characteristic is asymptotic. During this charging period, itwill be recalled, the tube V-Z is not conducting until the signal Abecame negative, and hence has no eitect upon the charge characteristic(see the wave shapes C of FIG. 3).

As soon as the tube V-Z becomes conducting, at the time M2, the flow ofcurrent through the tube V-Z will be the only factor limiting dischargeof the condenser C-4 and hence the discharge Will occur at a very highrate, 'as the constant plate current of the now conductive tube V-Z.This may be considered-a negative charging of the condenser, and it isquite linear also.

t is desirable for the purposes of this invention that the two portionsof the condenser potential signal C of PEG. 3 be linear, and theinvention includes means to assure this. Two 'different structures which`accomplish this with respect to the charge portion of the wave formwill be described, one being a simpler version than the other. Y

The condenser C-4 will continue to discharge along the right handportion of the triangular shaped wave shown at C in FIG. 3 until itfalls below zero. Thereafter, it will make the grid 115 of the left handsection of the twin triode V-S (said left hand section being hereinafterdesignated V-S-L) negative through V-4L. This signal will be amplifiedin V-S-L and appear at the plate 117, applied through the couplingcapacitor C-5 to the grid 113 and provide a signal on the -plate 119 ofV-5-R. The output signal is thus delayed from the occurrence of M2 asshown in FiG. 3 for the time that was required for the condenser C4 todischarge to zero.

In other words, the time at which the characteristic C intersects thebase line shown will occur after the time M2 which corresponds to acertain delay. This, in turn, depends upon the slopes of the charge anddischarge portions of the characteristic. The closer these slopes arecontrolled to linear the more readily will the apparatus provide asignal delay which varies inversely as the speed of the printing press.Varying the constants of the charge circuit will enable the slope tobe'changed, and if the circuit of discharge has not been changed, thedelay will be changed by a predetermined amount. Furthermore, decreasingthe time of the pulse between M1 and M2 as would be occasioned by anincrease in the speed of the press, would decrease the delayproportionally, as may be readily seen from the geometry of the waveshapes.

This latter occurrence is illustrated in FIG. 3 at D, E and F. Theselatter waves are identical to A, B and C respectively Vexcept: that thepress speed has been doubled. Note that the voltages and currents of theinput signals have not been changed in amplitude but the durations ofthe pulses have been halved. Because the charging of the condenser C-4lasted for only half of the time in F as in the case of C in FG. 3, C-4is charged to only half the'potential of C. The discharge with the samecurrent thus lasts only half as long and therefore the triangular waveshape subtends -precisely half the distance on the base line. Thisresults in a halving of the delay.

FIG. 4 demonstrates this in an enlarged view. The charge of thecondenser C-4 commences at a given speed of the press along the linelili) at the time M1 and follows the slope determined bythe constants ofthe circuit (and other factors which will be described) which ispreferably linear. M1 coincides with the flipper meeting the pole MC1.Thereafter the discharge occurs along a preferably linear line 162commencing at the point in time M2 which is when the llipper meets thepole MC2 and crosses the base line (zero volts) vat a time X. The delayproduced by the delay circuit is thus equal to the time elapsed betweenM2 and X.

The broken line curve of FIG. 4 is one which represents the charge anddischarge of the condenser C-4 at a speed of the press which is exactlytwo times the speed for the solid line curve of FIG. 4. The circuit isidentical .in all respects, and no changes have been made in the circuitconstants. In this case, choosing the starting time of charge as M1'coinciding on the iigure with M1, the charge characteristic followsprecisely the same line as the charge line 100 because the circuit andconstants are identical. When M2' time is reached, however, the flipper56 has reached the pole MC2. The elapsed time from M1' to M2' -isexactly half the elapsed time from M1 to M2. From the geometry of thetwo wave forms, obviously the length of the line 100" is half the lengthof the line 100. Discharge now commences along the line 102 and theslope 'of 102K is exactly the same as the slope of 102 and hence,the'characteristic is parallel therewith. Thus, the intersection X of102' with the zero base line provides a delay M2 to l l X' which is halfof the delay time M2 to X. So long as substantial linearity ispreserved, this will be true for any and all speeds of the Web 10, andin etect what has been accomplished has been to provide an angular delay(insofar as the signal from the cylinder 18 is concerned) which isindependent `of the speed of the press.

As previously stated, when the left hand sectionV-l-L and the tube V-Zare cut off, the condenser C-4 is being charged positively through thehigh ohmage resistor R-7. This charging characteristic will depend uponthe voltage of the junction point L1 which may be constant or variableduring the charging period. The latter circumstance is preferred, andthe presence of the tube V-3 enables this to be accomplished in a mannerto be described. The invention can be satisfactorily practiced, however,by maintaining the junction point J-1 at a relatively high voltage sothat the charging characteristic operates only upon the very beginningof the asymptotic characteristic obtained by charging from a fixedpotential. The voltage of this point is also manually adjusted bychanging the position of the slider of the potentiometer 54 which is thesame as the manual control shown in FIG. l. The potentiometer 54 is apart of a Voltage divider which includes the resistor R-17 and extendsbetween two potential points 66 and '73 which may be at differentvoltages. In the preferred embodiment which uses the tube V-3, thesevoltages are -150 volts D.C. and +1501 volts D.C. respectively, giving aspread of 300 volts. The potential is applied through a resistor R-9 tothe junction point I-l.

Since the delay which is applied to the signal from the magnetic timeris measured by the instant that the discharge characteristic carries thediode section V-4-L negative, the exact time that this will occurdepends upon the characteristics of the tube V-4. There may be aslightly varying contact potential existing in tube V4 such that thezero condition is not precisely dened. Unless the amplitude of thecharge and discharge characteristic is substantially greater than thisvery small potential, the small contact potential may become asignificant error. To prevent this, the charge and discharge slopes arepreferably made very steep, and in the case of the embodiment of theinvention which omits the tube V-3, this can be done by choosing thevoltage of the point J-1 to be very high, say of the order of 1000 ormore volts D.C. The charging rate will thus be increased along with theslope. The charging rate can also be increased by decreasing the ohmageof the resistor R-7, but this may be done at a sacriiice of linearity,and hence, the use of a higher voltage is preferable.

Summarizing the operation of the embodiment in which the voltage of thepoint J-l is fixed during discharge, prior to the time M1 the tubesection V-l-L is conducting saturation current; the tube V-Z is cut ofi;the condenser C-4 has zero potential and no charge across itselectrodes; there is no signal being applied to the tube section V1-R,and it is conducting saturation current. The manually controlledpotentiometer 54 has been adjusted to a position representing a givendelay, the dial of this control being calibrated in thousandths of aninch linear delay or the like. V-l-L keeps the junction point J-1 belowzero as needed, and there will be no eiect upon the condenser C-4because V-4-L will keep it at essentially zero voltage.

Continuing with the summary of the simpliiied embodiment, after thearrival of the negative going signal A, between the time M1 and the timeM2 the tube section V-1 is cut oi and presents substantially an ininiteirnpedance to the circuit, so that C-4 commences to charge toward thevoltage of the point I-l. During this period, V-l-R is still conductingsaturation current and V-2 is still cut oi. The voltage of the point l-lis controlled exclusively by the position of the slider of thepotentiometer 54, this being a circuit which excludes the tube V-3.

When time M2 is reached, the tube section V-1R gets the negative signalA', makes the plate 71 positive, applies a signal through C-S whichcauses grid 74 to become positive, and V-2 conducts such current aspermitted -by the screen 82 and controlled by the screen resistor R-tl.This is a constant current. The condenser C-4 discharges as the platecurrent of 4the tube V-Z, making the condenser more negative. Duringthis period of time V-l-L may or may not be still cut ol because theplate current of V-2 is so great compared to the current which could owthrough R-7 as to completely control the current iiow into C-i.

When the vvoltage on the condenser C-4 drops to zero (X in FIG. 4), thediode section V-4-L conducts, and as soon as current ows through theresistor R-ZZ, the tube section V-S-L amplilies the resulting signal,which is quite small, as does the section V-S-R and sends the resultingoutput into the comparison circuit to gate the signal from the scanner.The negative portion of the characteristic is the trigger for thescanner signal and hence since it occurs a delayed period after the timeM2, the effect will be as though the signal from the magnetic timer weredelayed.

Even a high voltage applied to the point l-l will produce a typicalcondenser discharge characteristic which is almost linear at itsbeginning, but is still logarithmic in nature. The greatest accuracy forthe requirements of the invention is achieved when the charge portion ofthe curve is practically perfectly linear. This is accomplished throughthe use of the novel circuit utilizing the tube V-3 in the mannerdescribed immediately below.

A voltage indicative of the voltage of the condenser C-4 is obtained onthe plate 104 of the left hand section V-3-L of the tube V-3. This plate104, it will be noted, is connected through the `load resistor R-14 tothe high voltage supply 65. The voltage of 104 is achieved through theeffect thereon of the grid 81 which in turn is connected to thecondenser C-4. There is a network R-19, R-20 and R-Zl between the plate104, plate 106, grid 108 and the negative potential point 66 which is at150 volts D.C. below ground. Ihis network causes a state of equilibriumto exist in which the voltage on the plate 106 of V-3-R is essentiallyopposite to the voltage on the plate 104 of V-S-L and therefore similarto the voltage on the grid 81 of V-S-L but displaced from it by aconstant D.C. value.

Consider a condition in which the grid 81 of V-3-L is at zero potential.Under this condition, the voltage on the cathode 110 will be at say plus14 volts D.C. The voltage at the plate 104 may be at about plus 230volts D.C. When the condenser C-4 commences to charge, it charges towarda potential which exists at the upper end of the resistor R-7 at thejunction point I-1, namely, the potential of the plate 64 of V-1-L. Asthe voltage on C-4 rises in value, the grid 81 must also rise, the plate10'4 decreases in voltage, the grid 108 decreases in potential becauseof the connection with the plate 104 through the resistor R-19, as aresult of which the plate 106 rises in potential. Since the upper end ofthe resistor R-7 is also tied to the plate 106 through the resistor R-10which is part of a voltage divider including the resistors R-9 and R-10,the upper end of R-7, that is point 1 1 will assume a voltage whichdepends not only upon the position of the wiper of potentiometer 54 butalso depends upon the voltage of the plate 106. `In this way, adjustmentof the potentiometer 54 varies the value of the D.C. potential by whichthe junction point J-1 is kept above the potential of C-4, this pointrising in potential as the condenser charges so that the slope of thecharge curve is linear because the voltage toward which the condensercharges is theoretically infinitely high.

The voltage on the plate 106 is controlled by the network R-19, R-20,R-Zl and R-IS which may be chosen so that for each volt of rise of thepotential of the condenser C-4, the plate 106 rises 2 volts, and throughvoltage divider action of R-9, R-10, the point 1 1 rises 1 volt.

The slope of the curve of the condenser charge under these circumstancesis controll-ed by the iixed D C. value set by lthe potentiometer 54 andthe capacitance of lche capacitor C4, and hence, the potentiometercontrols the Iamount of delay time enabling same to be varied at will.The resistor R-17 adjusts the range of the potentiometer 54 to zerodifferential in the lett extreme position of the wlper.

The effect of varying the potentiometer 54 is appreciated by consideringthe terminals of the potentiometer circuit. The right hand terminal ofthe potentiometer 54 is connected to 73` which is at +150 volts D.C.,and the other terminal is connected through the resistor R-17 to -150volts D.C., so that there is a total of 300 volts across thepotentiometer 54 and the resistor R-17 combined. This voltage will bedivided according to the resistances of the respective elements, and inone successful example, the ratio of resistances of 54 to R-17 was 30 to4.7 so that the voltage of the slider could be adjusted from -110 voltsDC. to +150 volts D.C. This voltage, modified by the effect of voltagedivider R-9, R-ltl is applied to the upper end of R-7 and controls theslope of the charge curve. Obviously, the slope will be steepest whenthe slider is at the right hand terminal of the potentiometer 541, andwill give the maximum delay. rhe minimum delay will occur when thevoltage toward which the condenser C4 charges is so low that the slopeof the charge curve will be practically Zero, and the discharge curvewill intersect the base line substantially `at the time M2. This will bea nullifying of the eilect of the circuit, and will ysimulate theapplication of the square wave of the input directly to the outputterminal 1115. Between these two extremes the delay is adjustable asdemonstrated in FIG. 5.

In FIG. there are illustrated twowave shapes, one of which issubstantially the same as the signal designated 100 `and A102 in FIG. 4,these characters representing the charge and discharge of the condenserC4. The other signal illustrated has a charge characteristic which isdesignated 1.10, of lesser Slope than the charge line 160, and adischarge line 112 which is parallel with the charge line 102` and willintersect -the base line at time z instead of time x. Consequently, theresulting delay will be Mz-z, `substantially less than M2-x, namely, inthe proportion of slopes of 100 and 110. It will be recognized that thedistance between M1 and M2 for both waves is the same, and thisrepresents therefore a constant speed of the press. This diagramillustrates lthe manner in which the movement of the slider of thepotentiometer 54 will change the delay.

The discharge curve 102 represents the discharge of the condenser C4.This commences immediately after there is a negative excursion of thesignal A at M2 during conduction of tube V-2. The plate current o V-Z iskept substantially constant, having the screen 812` tied through R-S tothe line 63, which is 150 volts D.C. above cathode 77. The resistor R-16lfrom screen grid 32. to plate y104- of V-3-L corrects secondary elects`from changing plate voltage since voltage of plate 104 varies in adirection opposite the voltage of plate 78. Because of this thedischarge will also occur at a linear rate.

The charge and discharge currents of the condenser C-4 are shown at Band E in FIG. 3 for two different speeds. Note that the negativedischarge current shown at 114, continues at a constant value rforsuliicient time for the delay to occur. The delay will result in thedischarge of the condenser C4 long enough to bring C4 to zero, referredto hereinabove as the intersection of the discharge line of signals C orF of FIG. 3 with the base line. When this occurs, the left hand sectionof the tube V-4 commences to conduct from cathode 80 to plate 86, andthe grid 115 of tube V-5 drops below zero cutting oit the ow of currentfrom the cathode 116 to plate 117, raising the grid 113 by way of thecoupling capacitor C45, and producing a triggering signal in the righthand section of -tube V-S which is applied through the terminal to thecomparison circuit 28. The output circuit is taken `from the terminal105 to ground, the terminal 105 Vbeing connected directly to the plate119 of V-S-R. This delayed signal can Vbe used in a manner described insaid. previously mentioned patents. The important portion of the signalis the negative going discharge portion 121 which is used for gating ortriggering or controlling relative to signals obtained from the scanner35.

The shape of the charge-discharge characteristic will determine thedelay produced, and -this can be changed in several different ways. Theslope of the charge curve is changed by the manual change of theposition of the potentiometer 54 which changes the voltage of the pointJ-1 toward which the charge occurs (of course with the added voltagewhen the tube V-3 is used in the circuit); the slope of the charge curvecan also be changed by using different values of the componentsinvolved, such as for example, the resistance of the resistor R-7 or thecapacitance of the capacitor C4; the slope of the discharge curve can bechanged by changing the circuit constants of the circuit of tube V-3,such as the value of resistor R-S. The simple manual variation of theresistance of the potentiometer 54 provides the easiest control of delayby varying only upon fthe'slope of the charge characteristic 109.

After the condenser C-4 has discharged and returns to zero, -asindicated by the curved line 121, the tube V-S returns to its stationarycondition. Until the next signal Ifrom the magnetic timer occurs, thesection V-l-R conducts saturation current and prevents C4 from chargingwith posi-tive current. The tube section V4L prevents C4 from assuming anegative potential so that the new cycle will always nd C-4 at zeropotential, giving accuracy to the control of delay.

The tube section V-4-R controls the potential of the screen 4grid S2during the period that V-2 is cut off. Such variations that m-ay occurin the voltage of the plate 7S of V-Z during charging of C4 can becompensated for by means of R-16 which extends between Ithe screen grid82 and the plate 104 of V-S-L, the latter being a point whose potentialvaries inversely with the voltage on the plate 78, as previouslymentioned.

The yfunctions of circuit components illustrated in the circuit but notspecifically mentioned are believed obvious. These include plate loadresistors, voltage dividing resistors, balancing resistors, and thelike. The circuit constants listed below will emphasize the nature ofthe component. The importan-t networks can be computed by usual networktechniques which need not be mentioned here to provide any desiredratios. The changes in voltage of the plate 106, condenser C4 and thejunction J-1 mentioned in the specification above were obtained With thenetworks involved having the values set `forth in the following detailsof a practical successfully operated structure:

R-l megohms-- 2.2 2 do 1.0 3 do 1.5 4 do 2.2 5 do .47 d do 4.7 7 ..d03.3 8 do 3.3 9 do 3.3 10 do 3.3 11 do 1.0 12 do.. .22 13 do 1.0 14 do.22 15 do .15 16 do 44.0 17 do .0'47

19 megohms 4.0 20 do 18.0 21 do 2.2 22 -do- .01 23 do .47 24 do 10.0 2Sdo 47 26 do l 27 do 22 29 do 047 30 do 47 31 do.. 1.0 32 do 1.0Potentiometer 54 do .3 Coupling capacitors C-1, C-Z, C-3 rnicrofarad .1Storage capacitor C-4 do .01 Coupling capacitor C-S do .Ol

Tube V-1 12AT7 Tube V-2 6AU6 Tube V-3 12AU7 Tube V-4 6AL5 Tube V-S 12AT7None of the laments are shown, but all are supplied from a suitabletransformer shown in the lower left hand corner of FIG. 2 with either 6volts or 12 volts, `as required.

It will be seen that the various tubes have basic functions which, ifpointed out, may aid in an understanding of the invention. V-1-L is agating tube section to incapacitate the elect of resistors R-7, R-9,R-lt until the iirst signal arrives. V-l-R is a control section toprogram the operation of the tube V-2, so that the discharge commencesat the proper time M2. V-Z, of course, is the discharge path forcondenser 0 4. V-3 is the tube which provides the constant D.C. voltageabove the potential of C-4 toward which the condenser C-4 charges, sothat the charge is linear, and is not essential to a basic structure,but is in a preferred embodiment. V-4-L is an isolating section betweenthe condenser C-4 and the amplifier tube V-S. V-4-R is a limiter forscreen grid 82 during the time V-Z is cut off.

The operation of the delay circuit described depends upon two signals.`The charge portion from M1 to M2 depends upon the square wave signal Awhich is derived from a flip-dop or other wave-shaping circuit. Thebeginning of the charge occurs at time M1 simultaneously with thenegative excursion of the square wave and the end occurs at M2. This endis simultaneous with the end of the negative square wave A, but the tubeV-2 which controls discharge is ungated by the section V-l-R which iscut off by the negative excursion of the signal A' that is injected at69. This latter signal A is derived from the magnetic timer 22 directlyor from the flip-flop circuit.

The delay described is the delay of the end of the magnetic timersignal, namely, delay of the time that the signal becomes Zero.

The signal from the scanner 35 could be delayed in a similar circuit.This is derived from photo-electric means. For example, the chargeportion of the circuit could be gated by a photoelectric signal obtainedfrom the beginning of a relatively long mark 16 and the discharge gatedby a second photoelectric signal obtained by the same photo-responsivecell from the end of the mark 16. An alternative structure would havetwo cells displaced from one another, both influenced by the arrival ordeparture of the mark.

The invention could also be practiced using the magnetic signal to startcharge and a photoelectric signal to start discharge, or vice versa.

Some reference should be made to several of the variations which arecapable of being made in accordance with the teachings of the inventionand without in any way departing from the spirit or scope of theinvention. As an example, the output signal represented by the chargeand discharge characteristics of the condenser C-4 should be examined.The specification has described means for changing the slope of thecharge line through the use of the variable potentiometer 54 to achievethe variation of delay in the signal, represented by the time between M2and complete discharge of the condenser C-4. This is M2-X in FIGS. 4 and5. The same effect can be achieved through variation in the slope of thedischarge line 102 maintaining the slope of the charge line constant.One way of varying the slope of the discharge line would be to vary theresistance of the resistor R-S and this has been indicated in FIG. 2 byshowing a broken line arrow through R-S, the arrow and resistor beingthe symbol of a variable resistor, aud the same being broken to showthat it is an alternate variation of the preferred embodiment.

In the claims which appear hereinafter, reference is at times made to atirst signal and a second signal. In the specification above, twoseparate signals were applied to the respective sections of the tube V-lat the terminals 59 and 69 respectively to provide gating for the chargeand discharge circuits of the condenser C-4. These signals aredesignated A and A', the signal A being a square wave and the signal Abeing a pulse obtained from the magnetic timer circuit MC2. The signal Awas shown to coincide in time with the trailing edge of the square wavesignal A. In the practical example, the pulses obtained when the tiipper56 passes the two poles of MC1 and MC2 are used to drive a tiipiiopcircuit which will provide the square wave A so that the signals A and Aare actually available.

The invention contemplates that the tube sections V-l-L and V-1-R willreceive signals at the times M1 and M2 which are either provided byseparate signal producing means; which are provided by a single signalproducing means which generates two signals in and of itself; or whichare provided by a single signal such as a square wave similar to signalA which is applied at terminal 59, while simultaneously being applied atterminal 69, but perhaps after first being shaped or modified to acondition which produces the desired function at 69. By this it is meantthat if the terminal 69 requires a negative going signal or any otherkind of signal, the shaping or modiiication can be done using suitableelectronic and/ or electrical elements such as other vacuum tubes,diodes, pulse-shaping networks and the like. Thus, where the languagerefers to tirst and second signais, it is intended to include signals orparts of the same signal, or having signiiicant characteristics relatedto a signal or signals to provide the necessary gating functions at M1and M2 regardless of how made.

The invention as described above has been applied to a machine, such asa printing press, in which a tiexible web moves relative to a stationperforming an operation thereof related in time to the performance of aprior act, such as for example, a prior operation on the same web. Theinvention does not necessarily require that there be a web movingrelative to the second station. The operation performed at the secondstation could be punching, forming, capping, printing, applying somearticle to another, or almost any other type of activity the time ofoccurrence of which can be related to the speed at which the object orobjects upon which the operation is performed reach the station, inaccordance with the invention.

It is desired therefore to be limited only by the scope of the inventionas delined in the appended claims, considered in the light of thebroadest range of equivalents which the prior art indicates.

What it is desired to secure by Letters Patent of the United States is:

1. In a system in which an object moving relative to a signal producingarrangement controls said arrangement to provide, respectively, a firstsignal and a second signal separate one from the other by a period oftime, the length of which time is inversely proportional to the speed ofmovement of said object; means for producing a third signal at a timedisplaced from the time of occurence of the second signal output by apredetermined delay varying linearly with the speed of movement of saidobject, said third signal producing means comprising, a capacitivecharging circuit normally inoperative, means connected in said chargingcircuit and gated by the iirst signal to render the said chargingcircuit operative, and a discharge circuit connected with said chargingcircuit and normally inoperative but including means rendering thedischarge circuit operative responsive to the occurrence of the secondsignal to discharge the charging circuit, the substantial discharge ofsaid capacitance `circuit forming said third signal.

2. A structure as claimed in claim 1 in which means are provided torender the charge and discharge characteristics each substantiallylinear.

3. A structure as claimed in claim l in which means are provided torender the charge and discharge currents of said capacitive chargingcircuit substantially constant.

4. A structure as claimed in claim l in which means are providedestablishing a potential point toward which said charging circuitcharges when rendered operative and said charging circuit includes meansraising said potential point by a constant additional potential abovethe charging circuit voltage during charging.

5. Structure as claimed in claim l in which means are providedestablishing a potential point toward which said charging circuitcharges when rendered operative, said means connected in the chargingcircuit comprises an electronic tube having at least a plate and acontrol electrode, said potential point is connected to said plate, apotential source is connected to said point, and said charging circuitincludes a capacitor also connected to said potential point, the tubebeing maintained conducting prior to the occurrence of the iirst signalwhereby to maintain said point at a constant low voltage and preventcharging of said capacitor, but rendered non-conducting by the saidiirst signal to permit the potential source to establish a highpotential at said point and the capacitor to charge toward saidpotential, the signal producing means being connected to apply the saidfirst signal to said control electrode.

6. Structure as claimed in claim 1 in which said means in the dischargecircuit includes an electronic tube having at least a plate and controlelectrode, and said charge circuit including a capacitor connected alsoto said plate, the electronic tube being normally non-conducting wherebyto have substantially no effect during charging of said chargingcircuit, and being rendered conducting by the second signal whereby todischarge the capacitor through said tube thereafter, said signalproducing means being connected to apply said second signal to saidcontrol electrode.

7. A structure as claimed in claim 1 in which means are providedestablishing a potential point toward which said charging circuitcharges when rendered operative and there is a source of potential andan impedance network including a variable impedance element connectedbetween said potential point and said source whereby variation of saidimpedance element will vary the potential of said point and hence therate of charge of said capacitive charging circuit which will in turnvary the time required for discharge thereof.

8. A structure as claimed in claim 7 in which said network includes avoltage divider having opposite ends thereof connected to terminals ofsaid source, one source terminal being variable to increase its voltagein predetermined ratio relative to the voltage of said capacitivecharging circuit during charging, whereby to continuously raise thevoltage of said potential point by a predetermined value exceeding thevoltage of said charging circuit during charging and render the chargingcharacteristie substantially linear.

9. A structure as claimed in claim 8 Yin which an amplier is connectedto said one source terminal having a signal from said capacitivecharging circuit connected as its input whereby the output follows theinput signal.

l0. A web system in which the web moves relative to two stations atwhich operations are respectively performed, said operations adapted tobe performed in registration, said system including signal producingmeans providing two signals related respectively to the operationsperformed at each station, one of saidsignals having two parts spaced bya time inversely proportional to the speed of the web, a comparisoncircuit having said signals applied thereto for comparing the twosignals to produce an error signal if the two signals are not properlyrelated for registration; means for delaying said second part of saidone of the signals applied to said comparison circuit whereby to varythe error signal, said delay being related to a given length of said webirrespective of the speed of the web and arranged to vary in accordancewith the web speed, comprising, a capacitive charge -and dischargecircuit including a condenser normally at zero charge potential, asource of potential including points of upper and lower value, ajunction point adapted to be placed at a positive potential, animpedance element connected between said condenser and said junctionpoint and the condenser adapted to be charged toward the potential ofsaid junction point, an impedance network including a manuallyadjustable impedance between said points of said source and saidjunction point adapted to apply a positive potential to said junctionpoint, a discharge circuit connected to said condenser, means normallymaintaining said junction at a low potential to prevent charging of saidcondenser, means normally maintaining said discharge circuitincapacitated, means for applying said first part of said one signal tosaid circuit to render said charging preventing means inoperativewhereby said condenser charges after said tirst part has been soapplied, and means for applying said second part to said incapacitatingmeans to render said incapacitating means inoperative whereby to causedischarge of said condenser through said discharge circuit and therebydelay the discharge of said condenser to vary said error signal for saidlength of web moved between the occurrence of the two parts of said onesignal in accordance with the speed of said web.

11. A structure as claimed in claim 10 in which means are provided tomaintain said junction point at a fixed voltage above the voltage of thecondenser at any time during the charging of said condenser.

l2. A structure as claimed in claim 10 in which means are provided tomaintain said junction point at a fixed voltage above the voltage of thecondenser at any time during the charging of said condenser, comprising,a ratio network controlled by the potential of said con`r denser.

13. A structure as claimed in claim 10 in which means are provided tomaintain said junction point at a iixed voltage above the voltage of thecondenser at any time during the charging of said condenser, comprisingan elec tronic amplifier having a plate output terminal and hav# ing thesaid condenser connected to its input whereby the output follows theinput by a predetermined constant increased voltage, and the said outputterminal is connected to said junction point.

14. A structure as claimed in claim l0 in which said discharge circuitcomprises a screen-grid controlled electronic tube.

15. A structure as claimed in claim 14 in which said screen-gridcontrolled tube has an element connected to said screen-grid whichmaintains current of said tube at a constant value, irrespective of thevoltage across said latter tube.

16. A structure as claimed in claim 14 in which means are providedlimiting the voltage on the screen-grid of 19 said tube during periodsthat said tube is not conducting current.

17. A structure as claimed in claim in which said condenser is connectedto an output circuit comprising an electronic amplifier, an isolatingelement between said amplifier and said condenser, and the amplifierhaving a path to ground to maintain said condenser at substantiallyground potential when said charging circuit is at said low potential.

18. A structure as claimed in claim 17 in which said isolating elementcomprises a diode.

19. In combination with a registration control device operating tomaintain registration of two operations performed on a moving web atstations spaced along the length of the web and in which there is afirst signal producing device producing a rst signal in synchronism withone operation, a second signal producing device producing a secondsignal in synchronism with said second operation, the signals eachhaving a duration inversely proportional to the speed of said web andadapted to have a predetermined occurrence relationship forregistration, having means for comparing said signals and producing anerror signal output when said operations are not in synchronism andcorrection means for changing the length of web subtended between saidoperations in response to said error signal to bring said operationsback into registration, means for electrically delaying one of thesignals to simulate physical adjustment of the position of one of saidsignal producing devices along the length of said web to change the saidoccurrence relationship for any condition of registration, whichcomprises, a delay circuit interposed between one of said signalproducing means and said comparing means and having a normally quiescentelectrical storage element therein, a substantially linear chargecircuit for said element operated by the beginning of the signal fromsaid one signal producing means and a normally inoperative substantiallylinear discharge circuit operated by the end of the said signal fromsaid one signal producing means, whereby the duration of the outputsignal from said delay circuit is varied for a fixed length of web inaccordance with the speed of said web, and means for changing theduration of said discharge to create an error signal for bringing saidoperations into registration.

20. The combination as claimed in claim 19 in which said last mentionedmeans comprises a manually variable circuit element in said chargingcircuit operable to change the rate of charge of said storage element.

2l. The combination as claimed in claim 19 in which said last mentionedmeans comprises a manually variable circuit element in said dischargecircuit operable to change the rate of discharge of said storageelement.

22. A structure as claimed in claim 2() in which said one of said signalproducing means is constructed to provide a substantially square waveoutput signal, and said storage element is a condenser, the charge anddischarge circuits of said condenser being substantially independent andthe charge and discharge characteristics forming the legs of a triangle,said circuit element comprising a resistor and the variation thereofserving to vary the slope of the leg of said triangle comprising saidcharge characteristic, without varying the slope of the other leg.

. 23. In an operation control device in which an object moves relaive toan operation performing station at which an operation is to be performedupon said object at a certain time related to the speed at which saidobject reaches said station, a correction means is provided for changingsaid speed to the proper rate, means are provided for producing firstand second signals separated by a time related to said speed, and meansare provided for driving said correction means in response to therelationship between the occurrence of said second signal and the timeof said operation; means for changing the last-mentioned relationshipwhich comprises, a charge-discharge circuit between said signalproducing means and said correction means for effectively delaying theoccurrence of said second signal and having substantially linear chargeand discharge characteristics, the charge portion of said circuit beinginitiated by said first signal and the discharge portion being initiatedby said second signal, and means for manually varying the rate of one ofsaid portions to vary the total time for charge and discharge to derivea signal having a desired relationship to the time of said operation fordriving said correction means accordingly.

24. In a registration control device in which a web moves relative to apair of spaced operation performing stations and a signal produced atsaid first operation performing station is adapted to be compared with asecond signal produced at a second operation performing station to makecorrection in the synchronism of operations performed; signal producingmeans at said first station producing said first signal with a durationwhich is inversely proportional to the web speed, means for delayingsaid signal prior to comparison with said second signal and comprising,a charge-discharge circuit having a linear characteristic, the chargestarting at the beginning of the first signal and the discharge startingat the end of said first signal, said discharge comprising the delay andbeing inversely proportional to the speed of said web to permit acomparison between said discharge and the second signal produced at saidsecond operation for introducing a correction in the synchronism ofoperations dependent on the speed of the web.

25. In a web detecting system wherein a plurality of successive signalsare derived each corresponding to a respective spaced apart movingposition on a web and having a time duration therebetween related to thespeed at which the spaced apart positions are moving and in which meansare provided for deriving a scanner signal corresponding to apredetermined position on said web, the improvement comprising meansoperated at a predetermined rate from a normal position responsive tothe appearance of the first of said plurality of signals, means forreturning said operated means to normal at a certain rate responsive tothe appearance of a second of said plurality of signals whereby the timeperiod in which said operated means returns to normal is dependent uponthe speed at which said spaced apart positions are moving, and meanscontrolled on return of said operated means to normal for providing alast signal related to the time interval between said first and secondsignals and therefore the speed at which said spaced apart positions aremoving to permit a comparison between said scanner signal and said lastsignal to be established on the basis of the speed of said certainpositions.

26. In the arrangement claimed in claim 25, means manually operated to aplurality of different positions for varying one of said rates tosimulate a change in the distance between said spaced apart positions,whereby the position of said last signal with respect to said scannersignal is varied for respective positions of said manually operatedmeans irrespective of said speed.

27. In a speed detecting circuit for deriving a signal related to thespeed of an object and having a pair of signal derivation elementslocated a fixed distance apart for deriving respective signals onsuccessive detection of said object movingly relative thereto, theimprovement comprising a gate circuit operated responsive to a signalproduced by one of said elements, charge-discharge means operatedlinearly at a predetermined charging rate and whose operation iscommenced by said gate circuit whereby the degree of operation iscontrolled in accordance with the length of time same is operated, andmeans operated responsive to a signal produced by the second of saidelements for resetting said charge-discharge means at a particulardischarge rate whereby the time period in which said charge-dischargemeans is reset is dependent upon its degree of operation.

(References on following page) References:4 Cited in the le of thispartent UNITED STATES PATENTS Kelling et a1. Nov. 7, 1950 10 22 CarbreyJuly 1, 1952 Casey Nov. 30, 1954 Palmer June 4, 1957 Fernsler Sept. 17,1957 Frommer June 24, 1958 Alhand June 24, 1958 Ropiequet et al. Sept.23, 1958 Casey Ian. 27, 1959 Grsdale Mar. 10, 1959

